Interventional medical devices, as a rising technique in the field of medical devices in recent 20 years, play important roles in reducing patients' trauma and improving the efficacy of disease treatment. An example for such a device is represented by an interventional device applied in a variety of lumens in a human body, such as an intravascular stent, a biliary stent, an esophageal stent, an intestinal stent, a pancreatic duct stent, a urethral stent or a tracheal stent et al., and the associated interventional catheter, balloon, filter and the like. Among them, the stent exhibits a particularly outstanding performance in the field of interventional medical devices. For various vascular diseases resulted from vascular obstruction or other causes, a stent has been proven to be a relatively successful interventional medical device for long-term implantation into the blood vessel. During an operation, the stent is delivered to location of a vascular lesion for block through a delivery system and then deployed. Thus, the blocked blood vessel is enlarged by the expanded stent and the patency is maintained.
In order to improve the effect of biocompatibility and the therapeutic effect of the interventional medical device in vivo, certain part of or the entire surface of the body of these devices can be coated with drugs and/or polymers. For example, the surface of the stent can be coated with a polymer layer containing drugs. When the stent with a drug-containing layer is implanted into a human body, not only that the obstructed blood vessel can be expanded to open by the stent, but also that the drugs in the drug-containing layer can be continuously released to the pathological vascular tissue that is in contact with the drug-containing layer. Thereby, a thorough treatment can be achieved.
However, because of the complexity of the physiological constitution of the human body, there is complicated biocompatibility problem associated with the interventional medical device itself in its application in a human body. In addition, the polymer coating material on the interventional medical device will also cause same biocompatibility problem in vivo. Commonly used polymer materials at present primarily include polymethacrylates, fluoropolymers, polyethylene-based polymers or polystyrene-based polymers, which are all used for industrial applications at the beginning and have poor biocompatibility.
Hence, the interventional medical device in the prior art may cause more serious thrombosis and post-operational complications after being implanted into a human body for an extended period of time due to its poor biocompatibility.